The long term goal of the proposed research is to develop computerized radiographic markers for assessing breast density and parenchymal structure that may be used together with clinical markers for use in determining risk of cancer. The specific objectives of the research to be addressed are: 1. Establish a database including mammograms, and family, gynecologic, diet and medical histories of women at low and high risk for breast cancer. 2. Develop computerized radiographic markers for characterizing the breast parenchyma through texture analysis for use in determining risk of breast cancer. 3. Evaluate the efficacies of the new computerized radiographic markers compared to current methods of risk assessment. The main hypothesis to be tested is that given a group of women, computerized analysis of their radiographic breast images should yield new techniques for identifying those women at risk for breast cancer. The applicants expect to obtain results that relate their new computerized radiographic markers to (a) currently used clinical indicators of risk (such as the Gail model), (b) biomarkers (BRCA/BRCA2 gene testing) of risk, and (c) actual onset of cancer.